Method of and apparatus for smelting ores



V. PAZOS Y SAC'IO.

METHOD OF AND APPARATUS FOR SMELTING ORES.

AI'PLICATION FILED APR. 26, 1919.

m1 9,76%. Patented June 13,1922.

2 SHEETSSHEET 1- &2 I 83 6 By A TTOR/VEVS came r VICENTE PAzos v SACIO, or NEWARK, NEW JERSEY.

METHOD OF AN D APPARATUS FOR SMELTING- ORES.

Specification of Letters Patent. Patentefl June 13, 1922.

Application filed April 26, 1919. Serial No. 292,867.

To all whom it may concern:

Be it known that I, .VICENTE PAzos Y SACIO, a citizen of Peru, South America, and a resident of Newark, in the county of Essex and State of New Jersey, have invented a new and Improved Method of and Furnace for smelting Ores, of which the following is a full, clear, and exact description.

This invention relates to a new and improved furnace, particularly of the shaft type, and to an improved method of operating furnaces in general.

Heretofore in smelting, particularly at high altitudes, great difliculty has been encountered in obtaining the required temperature to melt the metal, such as copper for example. In order to reach the melting point at all, it has been necessary to burn a greater amount of fuel at these relatively high altitudes, where relatively low atmospheric pressures are found, than would usually be required if the same smelting operation were carried out at the sea level or other place located at a lower altitude where there exists a higher atmospheric pressure. From this it is seen that a given amount of fuel will have a certain effective calorific capacity for smelting a definite amount of ore at the sea level atmospheric pressure,

. whereas if the same amount of fuel is used in smelting the same amount of ore at a higher altitude, where there exists the lower atmospheric pressure, it will be found that at this lower pressure the fuel will not smelt as much ore as at the higher pressure. Thus it is seen that at the decreased pressure the fuel has lost a certain part of its effective calorific capacity for smelting ores. This makes it uneconomical and in some cases impracticable to smelt ores in high altitudes.

One of the objects of this invention is to provide a means for smelting oreswhich may be applicable in carrying out a new and simpler method or process which will overcome the difliculties and objections above named in smelting ores.

In the present day practice in high altitude smelting of ores it is not practicable for the raw ore to be smelted directly in the shaft furnaces without preliminary roasting or other treatment. -VVhen this is done, certain of the impurities in the raw ore are burned or wasted, the heat from which if in smelting a more diversified and greater rangeof any kind of raw ores.

Another more specific object of this invention is to provide a new and improved furnace constructed to permit a new, improved and more simple method of smelting ores to be used, it being particularly applicable to high altitude smelting.

The above object is accomplished by providing a furnace constructed so that the fuel and gases may be burned under a pressure automatically maintained by suitable means.

Another advantage of burning the gases and fuel under pressure is that it eliminates in great part the difficulties which heretofore have been encountered in fiuxing highly refractory metal. This is of great advantage, in that under certain conditions of operation the fluxing .of the metal constitutes a "very expensive part of the smelting operation. Thus it is seen that in the application of a furnace of this type it makes prac ticable the smelting of ores at places in which heretofore it. has been entirely impracticable, due to fluxing difficulties.

Still a further object of this invention is to provide, within the furnace a compact and simple means for effectively and efficiently regenerating or utilizing within the furnace the heat of the slag, resulting from the smelting operation, which heretofore has been wasted. More specifically the above object is accomplished by providing a means for the furnace whereby the slag after leaving the crucible is granulated or formed into relatively small particles and travels through a chamber through which ascending air from a blower is conducted to the zone of combustion. In this manner, the heat of the slag heretofore wasted is transferred or imblower, which in a proper superheated form will tend to burn or oxidize out'the iron sulphide fromthe copper mat, thus leaving said mat in a more concentrated form.

A further function of the water as introduced is that it receives from the descendinggranules of slag the heat therein left by the air, and utilizes such heat in oxidation. The oxidizing effect of the oxygen, introduced in this manner as a component part of the water, more effectivelyfunctioning as a powerful oxidizer, than if merely introduced as in air. It may here be mentioned that by utilizing the oxygen of the water introduced in this manner, it is possible to change the character of the shaft furnace, which ordinarily is looked upon as a reducing furnace, to an oxidizing furnace. This is particularly desirable in the smelting of raw copper ores.

It is further to be noted in this connection that when the water is originally introduced with the air, it is turned to steam by the heat left in the slag after having contacted with the ascending air, and in this form as the steam approaches the combustion zone, its temperature is increased un if finally reaching the combustion zone it would be superheated at a relatively high tempera. ture.

Still a further object of this invention is to provide a furnace in which the fuel and gases are burned under a pressure and a means by which the pressure may be readily regulated, thus permitting a wide variation in temperature control which in turn gives a wide range in the slag control. By virtue of the simplicity thus obtained the great care heretofore necessary in smelting operations in the control of the slags is no longer reuired.

Still a further object is to provide a furnace constructed in such a manner as to obtain a more effective distribution of the air to the combustion zone. More specifically, this is obtained by providing planes of heated air instead of cones of heated air Other objects and advantages will appear from the following description and the accompanyin'g drawings in which similar reference characters'designate like parts in the several views.

Figure 1 is a sectional view in elevation of aeiavee the furnace showing the relative position of the parts of one of the preferred construetions.

Figure 2 is a plan view of the top portion of Figure 1.

Figure 3 is a plan View in section taken on the line 3-3 of Fig. 1.

Figure 4 is a sectional side elevation taken on the line 4- 1 of Fig. 1.

Figure 5 is a side elevation view partly in section taken on the line 55 of Fig. 1.

Figure 6 is an elevation view partly in section showing a modified form of the pressure regulating device.

It is to be understood that there is herein shown but onepreferred form ofa furnace for carrying out the new and improved process and method for smelting, it being particularly adapted to the shaft furnace in the smelting of raw ores, but may be used with other type of furnaces.

It is further to be understood that any suitable fuel, solid, liquid or gaseous, may be used to furnish the heat.

In the drawing showing one of the prewith themain shaft portion. this last-named portion being at that part of the furnace giving the highest temperature or the greatest amount of heat, thus functioning as the melting zone. The main shaft shell 5 is composed of a suitable heat insulating material and may be constructed in the usual manner Well known in the art.

Above the main shaft portion of the furnace there is provided a means for receiving. holding and feeding a charge to the main shaft portion of the furnace, it being understood that the charge will be made up with the proper proportions of ore. fluxing material and solid fuel, if used. in the desired proportions, which will var under the different conditions of operation. However. in the use of a furnace of this type in which the ore is smelted by burning the fuel under pressure, less difficulty will be encountered in properly fiuxing the ore and less fuel will be utilized for obtaining the heat necessary to reach the required temperature for melting the ore. The economy effected by burning the fuel. at a relatively high pressure, which may be six to eight pounds above atmospheric pressure, is here to be noted. Thus the heat of gases under pressure is conserved.

The means above the furnace for receiving a hollow'tube having the Wall 8 extending through the center of said receptacle, the

Way from the furnace through the upper part of the cup-shaped member, through the tube to the atmosphere. When the cup shaped member is seated to close the sageway, the smelting charge is held in the charging receptacle and there remains until the passageway leading from the charging receptacle to the shaft portion of the fur nace is opened by lowering the cup-shaped member.

A means is provided whereby the charging receptacle may be completely enclosed, for this purpose there being provided a fixed top portion 13 extending around the tube 8 and across the top of the charging receptacle, there being provided two hinged covers 14 and 15 which may be raised to permit the smelting charge to be dumped within the charging receptacle, but which will be closed thereafter to prevent escape of furnace gases therethrough when the closure member 11 is lowered to permit the charge to be carried within the shaft portion of the furnace.

It is understood that there is herein shown but one preferred arrangement of the members forming the char ing receptacle and the means of carrying a charge within the furnace, the essential feature being that the charging receptacle be normally closed to prevent material interference with the normal operating pressure within the furnace when the charging bell is lowered, a further essential feature being that there is provided a passageway from the main-shaft portion of the furnace to the outer atmosphere.

A very important feature of this invention is the provision of a means for automatically regulating and controlling the pressure within the furnace, thus determin ing the pressure at which the ore is smelted and at which the fuel is burned. To accomplish this purpose there is provided a coneshaped member 16 of such a shape that it may be seated at the end 17 of the tube 12 to form a closure therefor, said cone being carried by a. stem 18 from a cross bar 19, there being provided at each end of said cross bar, blocks 20 having flanges 21 projecting therefrom and extending on either side of guides 22 so that the cone may move up and down in a Vertical direction. As a means of controlling and regulating pressure within the furnace there are provided weights 23 from each end of the cross bar 19 by a suitable connecting member 24, it being understood that these weights may be varied and adjusted to suit the conditions of operation.

I do not limit myself to any particular arrangement for automatically maintaining a relatively constant pressure within the furnace. e

As a modification of the means shown in Figure 4, there is shown in Figure 6 a means for more readily adjusting the pressure by providing a bracket 25 carried by the tube 12 having pivoted at one end 26 thereof an arm 27, having connected therewith a cone member 16 arranged to be seated in the usual manner, and having at the other end thereof a weight 28 carried by a slide member 29- adapted to be moved at different parts of a toothed portion 30 of the arm 27 to obtain a variation of the furnace pressures if desired. An upwardly extending member 31, attached to the tube 12, serves as a guide to position the laterally extending arm 27.

Any suitable means may be provided to lower the tube 12 and bell or cup-shaped member 11 in order to permit the charge to fall in the shaft 1. In the present case this is done by providing a bar 32 having a bandie 33 and pivotally supported between theends of the bar on a rod 34, having each of its ends 35 carried in brackets 36 suitably carried by the sides of the charging receptacle. At the other end of the bar 32 there is provided a yoke 37 extending around the tube 12 and is pivotally connected to said tube by a pin 38 and link connection 39. The cup or bell-shaped member is held in a closed posit-ion when the handle 33 is down and is there held by a suitablehook or catch 39 pivoted from a fixed support herein shown as the floor 40, which is located adjacent the top of the charging receptacle 6 so that access may be conveniently had thereto.

An important feature of the arrangement herein shown is that when the smelting charge descends through the passage into the shaft portion of the furnace, the operating pressure of the furnace will not be materially changed because the pressure regulating means will still function and there will be no direct opening to the atmosphere through the charging receptacle which will be closed.

As a means of preventing excessively high temperatures of the furnace walls within the main melting zone of the shaft, there is provided a water jacket having the walls 40 and 41, around the lower restricted portion' of the shaft, forming an annular chamber 42 therearound through Which water is circulated, there being herein shown an inlet ipe 43 and an outlet pipe 44 for said than her. As an additional means of preventing excessive temperatures of the walls immediately above this portion of the shaft, there is provided a supplementary cooling means which comprises a pipe 45 surrounding the lower portion of the main shaft body, said pipe being provided with openings 46 through which the water passes forming a spray which plays upon the outer part of the furnace and is caught at a lower level by a water trough 47 surrounding the shaft at a point below the pipe 45. A suitable outlet pipe 48 is provided for the water trough. A supply pipe 49 and suitable control valve 50 is provided for the spray pipe 45 surrounding the furnace. A suitable control valve 51 is also provided for the intake pipe 43.

Another important feature of. this inven-- tion is a simple and effective means for conducting the air from the blast to the combustion zone. This is done by providing an enlarged annular chamber 52 around the lower part of the shaft and communicating therewith through which the air is forced to the combustion zone, it forming planes of air to the combustion zone instead of being carried thereto by cones or tuyeres, which has heretofore been the practice. The annular chamber is formed by having a cylinder 53 composed of suitable material extending around the lower portion of the furnace and spaced therefrom a 'sufiicient distance to form a chamber of the desired size. At the front of the furnace the cylindrical sides terminate in a front door portion 54 which has an opening 55 through which a trough 56 extends. Below the main shaft portion of the furnace to receive the meltedcharge made up of the mat and the slag, there is rovided the crucible 57, herein shown as icing supported on wheels 58 which travel on suitable rails 59 carried on a floor 60, the opening covered by the door 54 being of a suitable size to permit the crucible to pass,

therethrough. The crucible 57 is circular in form and constructed in the usual manner, the upper portion of the furnace comprising an annular body 60 forming the cylindrical receptacle 61 therein, which serves as a receiver for the mat and slag, but, it is understoodthat any suitable crucible may be used herein. An opening 62 is provided at the bottom of the receptacle 61 of the crucible, said opening extending through the crucible and forming a slightly inclined passageway, which serves as an outlet for the mat, terminating in the trough 56, from which the metal is drawn. At a higher level than the opening 62 there is provided another inclined passage 63 terminating in a trough 64 outside of the crucible, this latter passage serving as an outlet for tart tea the slag. The troiigh64-oniniiinicates with a heat regenerating chamber located at the bottom portion of the furnace through which I the air blast is conducted from the source of air supply to the combustion zone at the lower lpart of the main shaft of the furnace. This s aft comprises a main cylindrical body. 66 having suitable covering, the upper part of said chamber being provided with the top 67 which leads to the annular intake air chamber about the lower part of the main shaft. Within the upper portion of the heat regenerating chamber, there is provided a means for granulating, or dividing the slag into' relatively small portions as it falls or descends in said chamber, this being done in order that the air ascending in the chamber may more effectively take up or have transferred thereto the heat from the descending slag, thus in this manner, heating the air,

to a relatively high temperature, which 1s taken 'in at the combustion zone. By this method the heat in the slag heretofore wasted is very effectively utilized.

The lower portion of the regenerating chamber 68 is formed by a contracted cylindrical portion 69, which is connected to the upper portion by the conical section 7 0'. The particular form and size of the chamber may be varied, the essential feature being that it besuch as to insure the effective absorption of the heat from the descending slag by the air ascending from a suitable air blower 71, which is herein shown as being connected with the lower portion of the chamber by a suitable pipe connection 72.

As a means of effectively granulating or dividing the slag into relatively small portions, there is provided a rotating shaft 73 having spaced projecting fingers 74 extending radially therefrom, there being further provided stationary spaced finger members 7 5 extending from the wall of the heat regenerating chamber and offset from the projecting finger members 74 of the rotating member driven through pulley 96 on shaft 7 3 so that the revolving finger members pass between the stationary finger members. These members should be of a substantially heavy and massive construction and composed of a relatively good heat conducting material so as to afford a large surface with which the air may contact, thus tending to heat the air and at the same time keep the temperature of the slag granulating mechanism below the melting point. -Any other means well known in the art maybe provided for accomplishing the same purpose.

Another desirable feature of the echanism herein shown is that the' cooperation of the revolving and stationary'fingers besides graulating the slag acts as an automatic wiper or cleaner for the fingers, thus preventing an undesirable accumulation of the slag at this point. In operation it has been found at times that the slag outlet 63, if stopped or clogged, is a source of trouble, so therefore, there is provided an opening 76 in alignment with the slag trough and passage 64 and 63 respectively, having a suitable window or covering 77 therefor, through which the condition of the slag outlet and trough may be observed, and if it is noted that such passage is stopped, a suitable bar or tool may be inserted through said opening 76 in order to free the passage of any obstruction. As a means of observing the conditions within the lower portions of the furnace, there are provided peepholes 78' located around the enlarged annular portion of the furnace adjacent to the crucible.

By means of the air blast pump 71 and the pressure controlling mechanism carried at the top of the shaft, the desired pressure is maintained Within the furnace under which the ore is smelted. As the slag descends to the bottom of the heat regenerating chamber, there "must be provided a means for collecting and carrying away the slag, and this must be done Without materially interfering with the furnace pressure. To this end, there is provided at the lower part of the furnace a means which permits the above end to be accomplished. This is done by providing spaced cones 78 and 79 on a vertically slidable stem 80 carried at its upper end in a guide 81 and having connected at its lower end 82 a link 83 pivotally connected to an arm member 84 having a handle 85, said arm in turn being pivotally supported between its ends by a support 86. The lower portion of the heat regenerating chamber has a restricted cylindrical chamber 87, the lower portion of which forms a seat for the upper surface of the cone 79 so that when the cone is there seated, the lower end of the heat regenerating chamber is closed and permits the slag to descend and accumulate in said chamber 87. A portion of the air from the blower is conducted in said chamber by the pipe connection 88 so that as the air is taken within the heat regenerating chamber, it comes in intimate contact with the heated cone and the slag has the full length of the heat regenerating chamber to travel through.

The lowest portion of the heat regenerating chamber 87 is of a smaller diameter than the portion of the chamber immediately above so that there is formed a connecting tapered portion 89 which connects the chamber 87 with the upper portion of the heat regenerating chamber. This tapered portion 89 serves as a seat for the lower edge of the cone 78 when the stem is moved clownward so that the cone 79 is no longer seated upon the lower edge of the chamber 87. When the stem 80 is moved downward to cause the cone 78 to seat upon the tapered portion 89, the accumulated slag in the chamber 87 may be removed therefrom and while this is being done the cone 7 8 seated upon the tapered surface 89 serves as a stop to permit the accumulation ofthe slag thereabove, until the stem 80 is againraised to unseat said cone 78 and to again seat'the cone 79. The cone 79 is normally-maimt-ained in a seated position by a hook or catch 90, carried on a relatively fixed support 91, which engages the arm 84. To permit the slag to be taken from the chamber 87 the cone 78 is seated by releasing the hook 90 and permitting the stem 80 to be lowered. It is to be noted that an outlet for the granulated slag .is thus obtained with out materially interfering with the pressure within the furnace. It is also to be noted that there are provided the two inlets 92 and 93 for the air blast, the former entering the chamber adjacent to the cone 78 and the latter entering the chamber adjacent to the cone 79, thus insuring a proper air supply, irrespective of which cone is seated. A further advantage in having the air taken in at the points noted is that the air is required to pass throughout the entire length of the heat regenerating chamber, thus insuring that the maximum amount of heat from the slag will be taken up by the ascending air. A further advantage in having the air inlets adjacent to the respective cones is that it here contacts with the heated cone and the accumulated slag which here gives up the heat remaining therein after having descended through the main chamber portion.

Another very important feature of this inventionof the furnace and the improved method or process of smelting is the introducing of a limited quantity of moisture or water with the air blast which is taken in the heat regenerating chamber. As a means of doing this, there is shown a pipe 94 and a valve 95 therefor to regulate or control the amount of water used. The moisture thus taken in performs a double function in that it serves as a means, in addition to the air, to take up the heat from the slag as it travels through the heat regenerating chamber so that when it reaches the combustion zone, it will substantially be in the form of highly superheated steam.

A second highly advantageous feature of so introducing moisture in this manner is that the oxygen introduced in moisture in this manner is a more effective and powerful oxidizer of the ores than if introduced in air because, in order to obtain an equivalent effect if introduced in air, a much greater amount of air would have to be introduced in order to obtain the equivalent oxidizing effect, and by so doing there would be a great cooling action upon the furnace by the required increased volume of air. When the moisture reaches the combustion zone in the form of superheated steam and meets, for example sulphide of iron (,FeS), there will be formed oxide of iron (FeO) and hydrogen sulphide (H S), but the latter is immediately converted by the oxygen of the air blown in to water (H 0) and sulphurous oxide (S0 As the moisture has been heated to a relatively high temperature by the slag and is in the form of superheated steam when it reaches the combustion zone, when the reaction takes place, there will be consumed practically no heat of furnace ,combustion leaving the furnace at practically the same temperature.

It is to be noted here that the method of introducing moisture in this manner is not open to the objections heretofore made when moisture is carried to the combustion zone.

It is further to be noted that by utilizing the more powerful oxidizing efiect of the oxygen carried in the form of moisture'than when introduced in the air, the shaft furnace, which commonly is known as a reduction furnace, may be changed to an oxidizing furnace. This is of great advantage in smelting the raw ores of copper, because it enables-the raw ores to be directly introduced into the smelting furnace where the certain impurities are oxidized directly within the furnace and the heat therefrom conserved and used in the smelting operation. .Heretofore it has been found in many cases impractical to treat the raw ores directly in the smelting furnace, which has necessitated a preliminary treatment such as roasting after which the ore was then introduced into the smelting furnace. In most cases the quantity of moisture introduced would be equal to about one-tenth of the weight of the slag, but it is understood that the character of the ores treated and the conditions of operation will determine to great extent the proper amount to be used.

A further highly desirable feature of a furnace of this type in which the smelting is done under pressure is that it will enable the proper temperature and slag control to be had and thus eliminatethe difficulties heretofore encountered in properly fluxing the ore in smelting. This feature alone would make practical the smelting of ores in certain regions wherein heretofore it has.

been found exceedingly difficult, if not impractical, to properly smelt the ores due to the difficulties of fiuxing.

If in operation, a raw ore, as for instance of copper, is used in which there is an abundance of pyrites, there would be an abundance-of sulphur dioxide (S0 formed which would be readily changed to (S0 by forcing the escaping gases through water containing oxide of copper and through which a current of air is forced, thus giving rise to a weak solution of sulphuric acid,

which in turn could be used for the extraction of copper from poor ores.

As to the relation between the proper pressure and economy of operation, it is understood that this will vary with the ores used and conditions of operation, but for ex ample considering the copper ores and the temperatures at which such ores are smelted, eighteen pounds above atmospheric or thirtythree pounds absolute pressure would be approximately the maximum pressure which could economically be used because the small gain in calories would not warrant operation at higher pressures.

The passageway extending from the furnace to the atmosphere, and in which the pressure regulating device is positioned, should preferably be as short as possible in order to eliminate undue friction of the gases passing therethrough.

While but one preferred form of the furnace is herein shown and described, it is understood that various changes and modifications may bemade without departing from a the spirit and scope of this invention.

Having thus described the-invention what I claim as nevi is:

1. A furnace for smelting ores comprising a chamber for receiving the charge of ore, a crucible at the bottom thereof and spaced therefrom, an enlarged chamber extending around the bottom portion of the first-named receptacle, another chamber communicating with and extending below the crucible, a slag outlet from the crucible to said chamber means carried in the chamber below sai slag outlet to granulate the slag as it drops therefrom and a blower having an inlet at the lower portion of said chamber whereby the temperature ofthe ascending air in said chamber is raised by the heat taken from the descending slag.

2. A furnace for smelting ores comprising a main shaft portion, a crucible therefor,- a heat regenerating chamber communicating with the lower portion of the shaft adapted to cause the heat from slag to be transferred to air and steam, a slag trough leading from the crucible to said chamber and a means Within said chamber for granulating the slag from said trough.

3. A furnace for smelting ores comprising a main shaft portion, a crucible therefor, a heat regenerating chamber communicating with the lower portion of the shaft, a slag trough leading from the crucible to said chamber, a means within said chamber for granulating the slag from .said trough and an air blower having an inlet communicating with said heating chamber so that as the air travels to the main shaft portion of the furnace, it receives the heat from the granulated.

a main shaft portion, a crucible therefor, a heat regenerating chamber communicating with the lower portion of the shaft, a slag trough leading from the crucible to said chamber, a means within said chamber for granulating the slag from said trough, an air blower having an inlet communicating with said heating chamber so that as the air travels to the main shaft portion of the furnace, it receives the heat from the granulated slag and a means for introducing a regulated quantity of moisture with the air from said blast. i

5. A furnace comprising a shaft, a charging receptacle therefor, a passage communicating with said receptacle and said shaft, a closure for said passage, means for operating said closure, a passage extending through said closure means and communicating with the atmosphere and a pressure regulating device for said passage to maintain a relatively high pressure within the furnace.

6. A furnace comprising a shaft, a charging receptacle therefor, having an inclined bottom, an annular passage communicating with the upper portion of said shaft, a bell shaped member to act as a closure for said passage, another passage extending from the upper portion of said bell and forming an outlet to the atmosphere for the furnace gases and a means for said passage to regulate the furnace pressure.

7. A smelting furnace comprising a shaft, a charging receptacle having an inclined bottom, and an annular opening communicating with said shaft, a cone for closing said opening, a tube connected to the cone and communicating with the atmosphere, means for moving said tube and cone to permit the charging of the furnace, and a pressure regulating device for said-tube to maintain a relatively constant pressure within the furnace.

8. In a smelting furnace, a shaft portion, a normally enclosed charging receptacle thereabove having an opening communicating with said shaft portion, a movable cone for closing said opening a tubular member carried by the cone and forming a passageway in communication with the atmosphere and a means for said passageway for automatically regulating the furnace pressure.

9. A smelting furnace comprising a shaft, a crucible spaced therefrom to form an annular chamber at the lower part of the shaft, ameans within the furnace for regenerating the heat from .the slag, said means comprising a chamber communicating with the lower portion of the shaft and means within said chamber for breaking the slag into relatively small portions as the slag descends in said chamber.

10. A- smelting furnace comprising a shaft, a crucible spaced therefrom to form an annular chamber at the lower part of the shaft, a means within the furnace for regenerating the heat from the slag, said means comprising a chamber communicating with shaft, a crucible spaced therefrom to form an annular chamber at the lower part of the shaft, a means within the furnace for regenerating the heat from the slag, said means comprising a chamber communicating with the lower portion of the shaft, means Within said chamber for breaking the slag into relatively small port-ions as the slag descends in said chamber, a blower for introducing air'at the lower portion of said heat regenerating chamber and means for int-roducing a limited amount of moisture at the lower part of said chamber.

12. In a smelting operation, the method of regenerating heat which consists in breaking the slag into relatively small portions in a chamber communicatingwith the furnace .and carrying the air supply in contact with said relatively small portions,

13. In a smelting operation, the method of regenerating heat which consists in-breaking the slag into relatively small portions in a chamber communicating with the furnace, carrying the air supply in contact with said relatively small portions and introducing moisture within said chamber to also contact with the slag portions.

14. In a furnace for smelting raw ores, a shaft portion, a crucible spaced from the bottom portion thereof, a heat regenerating chamber communicating wit-h the lower portion of said shaft, means for maintaining a relatively high pressure within the shaft, said means including a blower connected with the heat regenerating chamber and a pressure regulating device carried at the upper part of the furnace.

15. A furnace for smelting raw ores under pressure comprising a shaft, a crucible therefor, a heat regenerating chamber communicating with the shaft, a slag trough leading to said chamber from the crucible, means within said chamber for granulating the slag and means to permit the slag to be taken from said chamber without substantial loss of furnace pressure, said means including a plurality of spaced cones and seats therefor, means for moving said cones and ar ranged so as to be successively positioned on their respective seats.

16. A pressure furnace comprising a shaft, a. crucible in the lower part thereof,

a heat regenerating shaft, means for forming the slag into relatively small portions and means for disposing of said slag without materially lessening the pressure of said furnace, said means comprising a stem, a plurality of cones carried thereon, a seat for the lower edge of said upper cone, a seat for the upper portion of said lower cone and means for moving said stem with the cones thereon so that when the lower cone is seated, the slag will be collected in the receptacle thereby formed and when the upper cone is seated, the slag previously collected above the lower cone will drop from the chamber. I

17. In a furnace for smelting raw ores under pressure including a heat regenerating chamber, a crucible, a slag trough for said crucible leading to said chamber, a means for granulating said slag into relatively small portions and a means for disposing of said slag without substantially decreasing the furnace pressure, said means including a plurality of spaced cone members, seats therefor, said cones functioning when seated to form a closed bottom for the heat regenerating receptacle, one of said cones forming, when unseated, an outlet from said chamber.

18. The method of conserving heat in the process of smelting raw ores, which consists in forcing air and a limited quantity of Water through a chamber in which granulated slag from the crucible is conducted and utilizing said heated air in the smelting of said ore.

19. The method 'of regenerating heat in the process of smelting ores, which consists in forcing air and a limited quantity of water in contact with the molten slag before said air and water reaches the combustion zone, and utilizing the resulting heated air and superheated steam in the smelting of a said ore.

20. In the method of smelting raw ores, the method of facilitating the oxidation of the ore, which consists in introducing a quantity of moisture with the air and heating said air and moisture to relatively high temperature by the use of hot slag before reaching the zone of combustion.

VICENTE PAZOS Y sAoIo; 

